The present invention relates to finFET semiconductor devices, and more specifically, to a finFET including an integrated silicon germanium/silicon (SiGe/Si) fin structure.
Conventional finFET semiconductor devices include a gate that fully wraps one or more semiconductor fins formed from Si. The wrapped gate can improve carrier depletion in the channel defined by the Si fin. Accordingly, electrostatic control of the channel defined by the Si fin may be improved.
Recent semiconductor fabrication methods have been developed to replace pure Si fins with SiGe fins. Forming the fins from SiGe reduces the threshold voltage (Vt) of the semiconductor device, thereby increasing the drive current that flows through the channel. Further, SiGe material provides higher carrier mobility than Si. Accordingly, SiGe fins may have improve electron hole mobility performance with respect to Si fins. Conventional methods, however, are limited to forming fins having a low concentration of germanium. Conventional methods may also form SiGe fins by epitaxially growing a SiGe layer from a Si seed layer, which forms a physical junction between the SiGe fin and the Si seed layer. Epitaxially growing the SiGe fin, however, may result in non-uniform fin grown and various defects that occur during the growth process.